Shearing head for dry shaver employing flexible shear plate and reciprocating cutter



Oct. 20, 1959 A. BRAUN ETAL 4 2,908,970

SHEARING HEAD EoR DRY sHAvER EMPLOYING FLEXIBLE SHEAR PLATE ANDRECIPROCATING CUTTER Filed Jan. 11. 1954 'all l Fig. 5

:NVMTORS l ARTUR BRAUN BODO FUTTERER ATTORNEYS frame.

United States Patent SHEARING HEAD FOR DRY SHAVER EMPLOY- ING FLEXIBLESHEAR PLATE AND RECIPRO- CATING CUTTER Artur Braun, Frankfurt am Main,and Bodo Ftterer,

Langen, Hessen, Germany, assignors to Max Braun, Frankfurt am Main,Germany, a partnership The present invention relates to the constructionof shearing heads of dry Shavers, and provides a construction wherebythe outer shear plate may be conveniently removed from the shaver andseparated from 4the inner cutter to facilitate cleaing of the shaver orreplacement of the shear plate.

Dry Shavers to which this invention relates consist in general, of aIbody member containing a driving unit terminating in and operating anoscillating drive pin. The shaving mechanism includes an outerstationary shear plate slotted or perforated to provide a plurality ofshear surfaces together with an inner cutter generally toothed toprovide cooperating shear surfaces and driven by Ithe oscillating drivepin. The shaving operation is performed by passing the shear plate overthe surface of the skin in such a manner that the hair to be shavedpasses through the slots or perforations in the shear plate and issevered by the cutter at the inner edge of the perforations. inasmuch ascutting occurs at the inner surface of the shear plate, that member isadvantageously made as thin las practical so that the hair may be cutoif `as close as possible. The shear plate accordingly is generallyqui-te fragile and flexible.

The present invention provides a shearing head construction in which theshear plate may be easily and safely removed from'the body of the shaverand from the inner cutter wi-th little or no danger of causing damage toit and by an entirely manual operation. struction thereby provides ashaving head which may be thoroughly cleaned with little effort, and -inwhich the shear plate may be easily replaced when that becomesnecessary.

In the construction provided by this invention, the

thin flexible shear plate is mounted in a frame which is detachablysecured to the shaver body, while the cutter is independently connectedwith the oscillating drive pin and independently spring-biased intoclose contact with the inner surface of the shear plate. In this manner,the shear plate is reinforced'and held in proper shape by the frame andmay :be removed from the shaver body and separated from the inner cutterto provide access to the cutting surfaces with little danger of causingit damage.

The shear plate is preferably a normally flat thin sheet of aresilient-ly ilexible metal bowed to provide a rounded shaving surfaceand ysecured at opposite edges to the Conveniently, opposite innersurfaces of the frame are formed with lugs engaging correspondingopenings in the edges of the shear plate, the resiliency of the bowedshear plate urging and assuring engagement of the openings with the lugsin the frame, while permitting easy removal of the shear plate simply byforcing its opposed edges inwardly to disengage the lugs. If desired,fhowever, the shear plate may Kbe secured to the frame by other meanssuch a-s screws or rivets.

The Vinner cutter,` it will be understood, is completely independent ofthe shear plate and frame but cooperates This con- I `with the shearplate against which it is urged -by one or more springs situated betweenVthe shaver bodyV and the cutter. In preferred embodiments, the cutteris mounted von the oscillating drive pin to prevent dislodgment of thecutter when the shear plate and frame are removed. Conveniently, the`dr-ive pin is provided with an enlarged end engaged within a recess inthe underside of the cutter which is retained on 'the `drive pin by itsenlarged head.

This invention will be better understood from the following ydetaileddescription of preferred embodiments thereof selected for purposes ofillustration and from the accompanying drawings in which:

Fig. l is a perspective view of the `shaving head of a dry shaverembodying the present invention;

Fig. 2 shows a cross-section end elevation of the shearing headconstruction of this invention;

Fig. 3 shows a cross-sectional lateral elevation of the embodiment shownin Fig. 2;

Fig, 4 is a longitudinal elevation in cross-section showing a furthermodification of the construction of this invention, and

Fig. 5 is a plan view of the shear plate normally eX- tended.

In the illustrated embodiments, the shaver body 1 containing the drivingmechanism, generally an electric motor, is provided with a shearing head10 consisting of a shear plate 12 secured to the body 1 by means of aframe 14, and an inner cutter 16 pressed against the inner ysurface ofthe shear plate 12 and driven across the lshear plate by an oscillatingdrive pin 18. The shear plate and cutter `are suitably of conventionalconstruction, the shear plate 12 being provided with a plurality ofclosely spaced narrow slots 2 0, the edges of which define cuttingsurfaces, and the cutter 16 being provided with a plurality of closelyspaced blades 21 conforming to the inner surface of the shear plate andcooperating with the slots v20 to effect shear cutting at the inneredges of the slots.

The frame 14 is generally in the form of a cowling mounted to the bodymember 1 at its upper end, which is preferably recessed so that theframe can be accommodated within the general contour of the body member.In the illustrated embodiments, the frame 14 is formed of opposite sidesegments 15 joined by outwardly bowed end segments 17, the latter havingrounded top edges extending above the side segments to provide anopening entirely surrounding the edges of the shear plate 12. To securethe frame 14 in place, the lower edge of each side segment 15 isprovided with a lip 22 which engages a bead 24 provided near the loweredge of the recessed top region of the body member 1. The frame thussnaps `in place, its inherent resiliency permitting the lip 22 to passthe bead 24 upon the application of a force tending to spread the sidesegments 15, which may lconveniently be applied by pressing the endsegments 17 together.

The cooperating lip and bead engagement of the frame to the body member1 suggested above, provides a particularly convenient means of securingthe frame to the body, but other well known engaging and securingmechanisms for instance, set screws threaded to the frame and engagingan appropriate abutting surface provided in the base member could, ifdesired, be used, or a spring latch in the body engaging a lip in theframe would be satisfactory.

The shear plate 12 consists of a normally at thin resilient sheet ofsuitable hard stock having openings 28 at its opposite side edgeportions, and is held within the frame in bowed relation with theopenings 28 engaging corresponding lugs 26 provided at the innersurfaces of the side segments 15. The bowed shear plate 12 thus providesa rounded cutting head surface which may be easily removed by furtherbowing the plate to permit the perforations 28 to disengage the lugs 26.

The cutter 16 is shown as comprising a plurality of parallel spacedcutting blades 2.1 shaped to correspond generally to the curvature ofthe shear plate 12 and formed on an arched base plate 19.

`In the embodiment shown in Figs. 2 and 3, the base plate 19 is providedon its underside with a pair of wells 30, accommodating springs 32supported at their other ends in corresponding seats 34 provided in theend of the body member 1. 4In this embodiment the drive pin 18 is in theform of a blade enlarged at its outer end. A pair of resilient pins 36extending across the bottom of the base plate 19 engage opposite sidesof the drive pin 18 whereby its oscillation causes the cutter toreciprocate. The enlarged head of the drive pin 18, it will be seen, isof width greater than the spacing of the pins 36 and prevents detachmentof the cutter from the body of the shaver.

In the embodiments shown in Fig. 4, the bottom of the cutter is providedwith a recessed region 40 and a drive plate 42 bored to accommodate theoscillating drive pin 18 is secured to and seated about the edges of therecess 40 as by a screw 43. To press the cutter against the shear plate,a spring 44 is situated around the drive pin 18 between an abutment 45provided at the base of the drive pin, and the drive plate 42. Thespring 44 thus urges the cutter outward from the drive pin and againstthe shear plate. lIn this embodiment, to prevent accidental dislocationof the cutter, the end of the drive pin y18 is grooved to receive asplit retaining washer 46 which forms an enlarged head preventingwithdrawal of the drive pin from the drive plate 42. `In thisembodiment, the drive pin and corresponding opening in the drive platemay be circular in cross-section to permit rotation of the cutter andaccess to its underside as well as access to the top end of the basemember 1.

In the preferred embodiment of this invention, the shear plate is ofextreme thinness, e.g. about .002 inch, and is accordingly quite exible.This feature has been found valuable since it obviates the necessity ofpreforming the cutter to correspond precisely in curvature with theinner surface of the shear plate. The flexibility of the shear plate inconjunction with the force urging the cutter against the' shear platecauses the curvature of the shear plate to conform to the curvature ofthe edges of the cutter blades, particularly in those areas where theouter surface of the shear plate engages the skin and is pressed by theskin into close engagement with the edges of the inner cutting bladesagainst the spring pressure applied to the cutter. Because of theflexible nature of the shear plate and the deformation it may thus besubjected to in the areas where it is pressed against the skin, areas ofthe plate not in contact with the skin may not closely engage thecutting blades, but the closeness and effectiveness of cutis not therebyimpaired.

It will further be seen that by mounting the shear plate in an easilydetached frame, while securing the cutter independently to the drive pinprovides extreme facility of cleaning while minimizing the danger ofdropping or damaging the shearing members. Removal of the frame andshear plate exposes the blades of the cutter so that the cuttingsdropping into the spaces between adjacent blades may be readily brushedout. Also when the frame and shear plate are removed, the cutter remainsin driven relation to the drive pin 18 so that by turning on the powerto shake the cutter back and forth after removal of the frame and shearplate, cuttings deposited in the spaces between the cutting blades maybe largely shaken out. Such a power cleaning operation is exceedinglysimple and facile.

Inasmuch as the driving mechanism actuating the drive pin forms no pantof the present invention, and may be of conventional construction wellknown to the art for imparting an oscillatory motion, a detaileddescription there;

'4 of is deemed unnecessary for a full understanding of this invention.The embodiments described above, it will also be understood, are givenby way of illustration, it being contemplated that obvious modificationswill occur to those skilled in the art, and may be made withoutdeparting from the scope of this invention.

Having thus disclosed our invention and described in detail preferredembodiments thereof, we claim and desire to secure by Letters Patent:

1. In a dry shaver having a body member, a drive pin, and driving meansfor oscillating the drive pin: a shearing head comprising a framedetachably secured to the body member about the drive pin, a shear platemounted to said frame, an inner cutter cooperating with the shear plate,spring means urging the inner cutter against the shear plate, linkingmeans on the under side of the inner cutter engaging opposite sides ofthe drive pin comprising a plate positioned under a recess in the innercutter and provided with an opening through which the drive pin projectsand an enlarged means on the end portion on said drive pin securing theinner cutter against detachment from the drive pin when said plate is inits aforesaid position.

2. A shearing head for a shaving implement having a body and drive meansfor reciprocating a cutter, comprising an inner cutter driven by saiddrive means and having a plurality of blades having edges convexlycurved in a plane transverse to the direction of reciprocation, an openframe surrounding said cutter detachably mounted at a fixed operablelocation on said body, a thin flexible resilient shear plate having hairreceiving openings and bowed into curved condition around the edges ofthe blades of said cutter and secured by its unbowed margins to opposesides of said frame with supporting means engaging the bowed portion ofthe shear plate entirely constituted by the edges of the blades of saidcutter, and means mounting said cutter in operable position includingresilient yielding means urging said cutter outwardly of the body andinto contact with the shear plate whereby when the bowed portion of theshear plate is held against the skin, the skin contacting area of theshear plate is conformed to the contour of the edges of the blades bythe pressure of the cutter.

3. A shearing head for a shaving implement having a body and anoutwardly extending drive pin for reciprocating an inner cutter,comprising an inner cutter driven by said drive pin and pivotallymounted thereto to swing in a plane transverse to the axis of said drivepin and having a plurality of blades having edges convexly curved in aplane transverse to the direction of reprocation, an open framesurrounding said cutter detachably mounted at a xed operable location onsaid body, a thin flexible resilient shear plate having hair receivingopenings and bowed into curved condition around the edges of the bladesof said cutter and secured by its unbowed margins to oppose sides ofsaid frame with supporting means engaging the bowed portion of the shearplate entirely constituted by the edges of the blades of said cutter,and means mounting said cutter in operable position including resilientyielding means urging said cutter outwardly of the body and into contactwith the shear plate whereby when the bowed portion of the shear plateis held against the skin, the skin contacting area of the shear plate isconformed to the contour of the edges of the blades by the pressure ofthe cutter.

4. A shearing head structure for a shaving implement comprising a bodyprovided with a head portion, a drive member mounted in said headportion for reciprocating a cutter, an inner overlying said drivemember, said cutter having a series of transversely directed cuttingblades spaced therealong and provided with cutting edges at the upperportions thereof, a head frame largely enclosing said cutter but havingan opening there- .r 4 m1-ln.pn

through adjacent said cutting edges, a shear plate secured to said headframe and having hair receiving openings disposed adjacent said firstmentioned opening, means detachably mounting said head frame in cutterenclosing position on the head portion of said body, spring means urgingthe cutting edges of said blades into engagement with the portion ofsaid shear plate which is provided with said hair receiving openings,means engaging said cutter with said drive member to afford upward anddownward movement of said cutter while maintaining the cutter in drivenrelation to the drive member, and means affording power cleaning ofcuttings from the spaces between the blades including means holding saidinner cutter against detachment from said drive member when said headframe and shear plate are detached from said body, whereby said cutterremains in driven relation to said drive member when said head frame andshear plate are detached.

5. A shearing head structure for a shaving implement comprising a bodyprovided with a head portion, a drive member mounted in said headportion for reciprocating a cutter, an inner cutter overlying said drivemember, said cutter having a series of transversely directed cuttingblades spaced therealong and provided with curved cutting edges at theupper portions thereof, an open frame largely enclosing said cutter buthaving an opening therethrough adjacent said cutting edges, a thinflexible resilient shear plate carried by said frame 'and havingopposite side edgeportions secured respectively to opposite sidesegments of said frame, said shear plate having an intermediate portionbetween said side edge portions which is vprovided wtih hair receivingopenings, said intermediate portion having a bowed shape and disposedadjacent said lirst mentioned opening with supporting means engaging thebowed portion of the shear plate entirely constituted by the edges ofYthe blades of said cutter, means detachably mounting said frame incutter enclosing position on the head portion of said body, spring meansurging the cutting edges of the blades into engagement with saidbowed'portion of the shear plate, with the aforesaid frame and shearplate positioned with said inner cutter to afford conformance incurvature between the portions of said shear plate and cutting bladeswhich are urged into engagement one with the othere by said springmeans, and means affording power cleaning of cuttings from the spacesbetween the cutting blades including means holding said inner cutteragainst detachment fromsaid drive member when said frame and said shearplate carried Vthereby are detached from said body, whereby said cutterremains in driven relation to said drive member when said frame andshear plate are detached.

6. A shearing head structure for a shaving implement comprising a bodyprovided with a head portion, a drive member mounted in said headportion for reciprocating a cutter, an inner cutter overlying said drivemember, said cutter having a series of transversely directed cuttingdetachably mounting said head frame in cutter enclosing position on thehead portion of said body, spring means urginzr the cutting edges ofsaid blades into engagement with said bowed portion of the shear plate,means engaging said cutter with said drive member to afford upward anddownward movement of said cutter while maintaining the cutter in drivenrelation to the drive member, and means holding said inner cutteragainst detachment from said drive member when said head frame and saidshear plate carried thereby are detached from said body, whereby saidcutter' remains in driven relation to said drive member when said headframe and shear plate are detached.

7. Dry shaving apparatus comprising, in combination, a casing a shearplate carrier affixed to said casing, a iiexible shear plate having aconcave lower surface and two longitudinal edges and affixed to saidcarrier only at said longitudinal edges to be deformable in respect ofthe curvature of said lower surface, a lower blade having a cylindricalcutting surface and mounted with freedom of lateral translation andreciprocation in respect of the axial direction of its coating surface,a drive mechanism contained in said casing and operatively connected tosaid lower blade for reciprocating the same in the axial direction ofits cutting surface, and at least one compression-elastic andomnidirectionally fleXure-elastic member extending transversely to saidcutting surface and having one end undisplaceably held relative to thecasing and another end undisplaceably held relative to the lower blade,whereby said lower blade is urged against said lower surface of saidshear plate and held with freedom of lateral translation, and said shearplate is caused to adapt to the form of the lower blade and at the sametime forms, a yielding guide for the lower blade.

References Cited in the tile of this patent UNITED STATES PATENTS2,174,039 Muros Sept. 26, 1939 2,196,098 Bruecker Apr. 2, 1940 2,200,186Muros May 7, 1940 2,234,893 Bruecker Mar. 11, 1941 2,296,093 DalkowitzSept. 15, 1942 2,526,153 Page Oct. 17, 1950 2,688,184 Jepson Sept. 7,1954 2,691,216 Ross Oct. 12, 1954 UNITED STATES PATENT OFFICECERTIFICATE OE CORRECTTON l 1Patent No.l 2,908,970 October 20., 1959Artt@ Braun iet 'aL VW printed specification It is herebj'y certifiedthat error appears in the that the said Letters of the above numberedpatent requiring correction and Patent should read as corrected below.

Signed and sealed this 10th day of May 1%@o (SEAL) Attest:

ROBERT C. WATSON KARL lH. .XlIlW-l Attesting4 Ofcer Commissioner ofPatents

